U.S. patent application number 10/835956 was filed with the patent office on 2005-11-03 for liquid loop with multiple pump assembly.
This patent application is currently assigned to Hewlett-Packard Development Company, L.P.. Invention is credited to Malone, Christopher G., Simon, Glenn C..
Application Number | 20050244280 10/835956 |
Document ID | / |
Family ID | 34574907 |
Filed Date | 2005-11-03 |
United States Patent
Application |
20050244280 |
Kind Code |
A1 |
Malone, Christopher G. ; et
al. |
November 3, 2005 |
Liquid loop with multiple pump assembly
Abstract
A pump assembly includes inlet and outlet interfaces capable of
coupling to a liquid cooling loop tubing, a plurality of pump
connectors coupled to the inlet and outlet interfaces enabling
pluggable connection of a plurality of pumps to the inlet and
outlet interfaces, and a controller. The controller is coupled to
the plurality of pumps and controls power levels of the individual
pumps, enabling control of fluid flow rate in the liquid cooling
loop.
Inventors: |
Malone, Christopher G.;
(Loomis, CA) ; Simon, Glenn C.; (Auburn,
CA) |
Correspondence
Address: |
HEWLETT PACKARD COMPANY
P O BOX 272400, 3404 E. HARMONY ROAD
INTELLECTUAL PROPERTY ADMINISTRATION
FORT COLLINS
CO
80527-2400
US
|
Assignee: |
Hewlett-Packard Development
Company, L.P.
Houston
TX
|
Family ID: |
34574907 |
Appl. No.: |
10/835956 |
Filed: |
April 29, 2004 |
Current U.S.
Class: |
417/286 ;
257/E23.098; 417/572 |
Current CPC
Class: |
H05K 7/20772 20130101;
F04B 2205/09 20130101; H01L 2924/0002 20130101; H01L 2924/00
20130101; F04B 23/06 20130101; F04B 19/006 20130101; H01L 23/473
20130101; H01L 2924/0002 20130101 |
Class at
Publication: |
417/286 ;
417/572 |
International
Class: |
F04B 049/00; F04B
039/00 |
Claims
What is claimed is:
1. A pump assembly for an electronic liquid cooling system
comprising: inlet and outlet interfaces capable of coupling to a
liquid cooling loop tubing; a plurality of pump connectors coupled
to the inlet and outlet interfaces enabling pluggable connection of
a plurality of pumps to the inlet and outlet interfaces; and a
controller capable of coupling to the plurality of pumps and
controlling power levels of the individual pumps, enabling control
of fluid flow rate in the liquid cooling loop.
2. The pump assembly according to claim 1 further comprising: a
plurality of pumps coupled to the plurality of pump connectors, the
number of pumps in the plurality of pumps being at least one higher
than a minimum to meet system cooling specifications.
3. The pump assembly according to claim 1 wherein: the plurality of
pump connectors connecting the plurality of pumps in a
configuration selected from among a group consisting of a serial
connection, a parallel connection, and a combination serial and
parallel connection.
4. The pump assembly according to claim 1 wherein: the number of
pump connectors accommodates a sufficient number of redundant pumps
more than a minimum to meet system cooling specifications so that
less expensive and less reliable pumps may be used with higher
reliability.
5. The pump assembly according to claim 1 wherein: the controller
can operate in a mode in which a redundant pump of the plurality of
pumps is non-operational until the controller predicts or detects a
failure condition.
6. The pump assembly according to claim 1 further comprising: a
check valve associated with a pump of the plurality of pumps to
prevent back-flow through a non-operating pump.
7. An electronic liquid cooling system comprising: a tubing
enclosing an interior bore or lumen within which a cooling fluid
can circulate; a plurality of pumps having pluggable connections to
the tubing, the number of pumps in the plurality of pumps being at
least one higher than a minimum to meet system cooling
specifications; and a controller capable of coupling to the
plurality of pumps and controlling power levels of the individual
pumps, enabling control of fluid flow rate in the liquid cooling
loop.
8. The system according to claim 7 further comprising: a check
valve associated with a pump of the plurality of pumps to prevent
back-flow through a non-operating pump.
9. The system according to claim 7 wherein: the plurality of pumps
connects the plurality of pumps in a configuration selected from
among a group consisting of a serial connection, a parallel
connection, and a combination serial and parallel connection.
10. The system according to claim 7 wherein: the number of pumps is
sufficiently more than a minimum to meet system cooling
specifications so that less expensive and less reliable pumps may
be used with higher reliability.
11. The system according to claim 7 wherein: the controller can
operate in a mode in which a redundant pump of the plurality of
pumps is non-operational until the controller predicts or detects a
failure condition.
12. The system according to claim 7 wherein: the controller is
capable of detecting the number of pumps connected to the tubing
and a maximum heat load, and controlling power levels of the
plurality of pumps accordingly.
13. An electronic system comprising: a chassis including airflow
inlet and outlet vents; a plurality of components including
heat-generating components mounted within the chassis; and an
electronic liquid cooling system comprising: a tubing enclosing an
interior bore or lumen within which a cooling fluid can circulate;
a plurality of pumps having pluggable connections to the tubing,
the number of pumps in the plurality of pumps being at least one
higher than a minimum to meet cooling specifications based on
conditions imposed by the heat-generating components; and a
controller capable of coupling to the plurality of pumps,
determining thermal conditions internal to the electronic system,
and controlling power levels of the individual pumps based on the
thermal conditions, enabling control of fluid flow rate in the
liquid cooling loop.
14. The system according to claim 13 further comprising: a check
valve associated with a pump of the plurality of pumps to prevent
back-flow through a non-operating pump.
15. The system according to claim 13 further comprising: the
plurality of pumps connects the plurality of pumps in a
configuration selected from among a group consisting of a serial
connection, a parallel connection, and a combination serial and
parallel connection.
16. The system according to claim 13 wherein: the number of pumps
is sufficiently more than a minimum to meet system cooling
specifications so that less expensive and less reliable pumps may
be used with higher reliability.
17. The system according to claim 13 wherein: the controller can
operate in a mode in which a redundant pump of the plurality of
pumps is non-operational until the controller predicts or detects a
failure condition.
18. The system according to claim 13 wherein: the controller is
capable of detecting the number of pumps connected to the tubing
and a maximum heat load, and controlling power levels of the
plurality of pumps accordingly.
19. A method of cooling an electronic system comprising:
configuring a liquid loop cooling system with a plurality of pumps,
the number of pumps being at least one higher than a minimum to
meet cooling specifications based on thermal conditions within the
electronic system; determining thermal conditions within the
electronic system; and controlling power levels of the individual
pumps based on the thermal conditions.
20. The method according to claim 19 further comprising:
maintaining a redundant pump of the plurality of pumps as
non-operational; predicting or detecting a failure condition; and
in response to the failure condition, commencing operation of the
redundant pump.
21. The method according to claim 19 further comprising: detecting
the number of pumps connected to the liquid loop cooling system;
detecting a maximum heat load of the electronic system; and
controlling power levels of the plurality of pumps according to the
detected number of pumps and maximum heat load.
Description
BACKGROUND OF THE INVENTION
[0001] Electronic systems and equipment such as computer systems,
network interfaces, storage systems, and telecommunications
equipment are commonly enclosed within a chassis, cabinet or
housing for support, physical security, and efficient usage of
space. Electronic equipment contained within the enclosure
generates a significant amount of heat. Thermal damage may occur to
the electronic equipment unless the heat is removed.
[0002] As electronic components and subsystems evolve to increasing
capability, performance, and higher power, while reducing size and
form factor, efficient and cost-effective removal of excess heat is
desired. Among available thermal management solutions, liquid
cooling via cold plate technology offers high capacity for heat
rejection and movement of heat from internal sources to external
ambient air. Liquid cooling loop systems typically cycle pumped
coolants continuously, conveying excess heat from heat-generating
devices. The heat is dispersed into ambient air using a heat
exchanger or other device.
[0003] A liquid loop cooling system generally uses a pump to drive
the cooling fluid through high pressure-drop channels of cold
plates attached to processors and other high-power components, and
along potentially long and narrow-diameter tubes forming the loop
between cold plates, condenser, and pump.
[0004] Pumps have a finite lifetime of operation. The pump in a
liquid cooling loop system introduces a single-point of failure, a
substantial weakness in system reliability. A common liquid cooling
loop implementation uses a single loop to cool all processors in a
system. The single point-of-failure presented by the pump increases
system susceptibility to catastrophic failure in the event of pump
failure that causes some or all processors to overheat.
SUMMARY
[0005] In accordance with an embodiment of an electronic liquid
cooling system, a pump assembly includes inlet and outlet
interfaces capable of coupling to a liquid cooling loop tubing, a
plurality of pump connectors coupled to the inlet and outlet
interfaces enabling pluggable connection of a plurality of pumps to
the inlet and outlet interfaces, and a controller. The controller
is coupled to the plurality of pumps and controls power levels of
the individual pumps, enabling control of fluid flow rate in the
liquid cooling loop.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the invention relating to both structure and
method of operation, may best be understood by referring to the
following description and accompanying drawings.
[0007] FIG. 1 is a perspective pictorial diagram showing an
embodiment of an electronic liquid cooling system that includes a
multiple pump assembly.
[0008] FIGS. 2A, 2B, and 2C are schematic block diagrams
illustrating various embodiments of multiple pump assemblies.
[0009] FIGS. 3A and 3B depict a perspective pictorial diagram and a
schematic mixed pictorial and block diagram illustrating an
embodiment of a suitable mechanical pump for usage in a multiple
pump assembly.
[0010] FIG. 4 is a perspective pictorial diagram illustrating an
embodiment of an electro-osmotic pump that may be used in an
electronic liquid cooling system.
[0011] FIG. 5 is a schematic pictorial diagram showing an
embodiment of an electronic liquid cooling system with redundant
pumps and a controller capable of managing the pumps.
[0012] FIG. 6 is a perspective pictorial diagram that illustrates
an embodiment of an electronic system, for example a computer
server, including a multiple pump assembly and controller to manage
pump redundancy.
DETAILED DESCRIPTION
[0013] A disclosed electronic liquid cooling system includes a
redundant pump configuration to increase reliability, thereby
eliminating the weakness of a single point-of-failure
implementation. Multiple or redundant pumps ensure maintenance of
acceptable cooling performance. Addition of pumps beyond the
minimum enables what is termed "N+1 pump operation" in which N is
the minimum number of pumps that attains acceptable cooling levels.
Redundant pumps may be arranged in a parallel or series, depending
on characteristics of the underlying pump technology.
[0014] Referring to FIG. 1, a schematic block diagram illustrates
an embodiment of an electronic liquid cooling system 100 that
includes a multiple pump assembly 102. The multiple pump assembly
102 includes inlet 104 and outlet 106 interfaces capable of
coupling to a liquid cooling loop tubing 108. A plurality of pump
connectors 110 are coupled to the inlet 104 and outlet 106
interfaces to enable pluggable connection of a plurality of pumps
112 to the inlet 104 and outlet 106 interfaces. The pump assembly
102 also includes a controller 114 that is coupled to the plurality
of pumps 112 and controls power levels of the individual pumps,
enabling control of fluid flow rate in the liquid cooling loop.
[0015] The plurality of pumps 112 can be added to the multiple pump
assembly 102 by coupling to the plurality of pump connectors 110.
The number of pumps 112 can be selected to be at least one higher
than a minimum to meet system cooling specifications. Some pump
assembly embodiments may support even higher redundancy. For
example, the number of pump connectors 110 may be selected to
accommodate a sufficient number of redundant pumps 112 more than a
minimum to meet system cooling specifications so that less
expensive and less reliable pumps may be used while assuring higher
reliability.
[0016] The controller 114 is connected to the pumps 112 to supply
pump signals controlling flow rates of the individual pumps. The
controller 114 can selectively drive flow through particular pumps
while discontinuing flow through one or more other pumps. For
example, the controller 114 can operate in a mode in which a
redundant pump of the plurality of pumps 112 can be held
non-operational until the controller 114 predicts or detects a
failure condition, thereby maintaining the redundant pump in
reserve. In response to selected conditions, the controller 114 can
activate a redundant, deactivated pump to meet instantaneous
cooling demand, enhancing reliability by avoiding or eliminating
usage of the redundant pump until warranted by conditions.
[0017] During an "N+1 pump" operation, the controller 114 can
operate the electronic liquid cooling system 100 to support a
maximum heat load and, when the load is lower, scale back the pump
performance to match the load. Alternatively, the load can be
controlled by processor throttling techniques. Accordingly, the
controller 114 continues to operate the electronic liquid cooling
system 100 in N pump mode operation, although at a reduced
performance.
[0018] Also during the N+1 pump mode operation, the controller 114
can save energy by operating all pumps at a reduced level. When
operation is changed to N pump mode, the functioning pumps may be
operated at full capacity.
[0019] The illustrative electronic liquid cooling system 100
further includes at least one heat exchanger 116, at least one cold
plate 118, and at least one expansion valve 120 to manage
dual-phase flow. The cold plate 118 transfers heat from electronic
devices and components to cooling fluid in the tubing 108. The heat
exchanger 116 transfers heat from cooling fluid in the tubing 108
to the air for removal.
[0020] The connectors 110 can be quick-disconnect connectors that
enable hot-pluggable functionality. The pumps 112 can be
hot-pluggable to enable safe removal and insertion without
interrupting system operation. Quick disconnect connectors 110
enable engagement and disengagement from the electronic liquid
cooling loop without loss of liquid.
[0021] In a particular embodiment, quick-disconnect connectors can
be used for pumps connected in series to enable field replacement
of non-functional units.
[0022] Referring to FIGS. 2A, 2B, and 2C, schematic block diagrams
illustrate various embodiments of multiple pump assemblies 200,
202, and 204, respectively. The plurality of pump connectors can
connect the plurality of pumps 206 in a configuration selected from
among a group consisting of a serial connection 202, a parallel
connection 200, and a combination serial and parallel connection
204. In some embodiments, a check valve 208 may be used to prevent
back-flow through a non-operating pump.
[0023] An electronic liquid cooling system typically uses kinetic
or positive displacement mechanical pumps. Referring to FIGS. 3A
and 3B, a perspective pictorial diagram and a schematic mixed
pictorial and block diagram illustrate an embodiment of a suitable
mechanical pump 300 for usage in a multiple pump assembly. The
mixed pictorial and block diagram illustrated by FIG. 3B depicts
end and side views of the pump 300. The mechanical pump 300 has an
input port 302 and an output port 304 that connect to quick-release
type connectors to enable hot-pluggable connection and removal of
the pump 300. The pump 300 is driven by stepper motor coils 306
that rotate an internally-threaded rotor 308, moving a screw 310. A
plunger 312 connected to the screw 310 discharges liquid inside the
pump 300 through the output port 304. A sensor 314 inside the pump
300 detects motion of the plunger 312 and generates a pulse
electrical signal that can be used for control and monitoring
operations. Pump discharge and suction volumes can be controlled by
monitoring pulse number and selectively driving the motor coils
306.
[0024] Alternative pump technologies may otherwise be used for an
electronic liquid cooling system, for example using piezo-electric
crystals and/or electro-osmosis. Referring to FIG. 4, a perspective
pictorial diagram illustrates an embodiment of an electro-osmotic
pump that may be used in an electronic liquid cooling system.
Electro-kinetic effects arising from electrochemical reactions at a
liquid-solid phase interface can be used to generate pumping action
in miniature systems. Electro-osmosis is an electro-kinetic effect
that may be useful to pump liquids in microscale systems. An
electro-osmosis pump may be constructed by various techniques,
including micro-machining.
[0025] The illustrative example shows an electro-osmosis pump 400
including a micro-machined etched silicon substrate 402. Slots 404
with a large ratio of perimeter to cross-sectional area are
deep-etched into the substrate 402. The cross-sectional area of
pumping determines pumping flow rate is selected and implemented by
varying the number of slots 404. The number of slots is
proportional to flow rate. In some embodiments, the substrate 402
may be coated with a silicon nitride layer to passivate the silicon
substrate and enable operation at relatively high voltage levels,
for example in the range of hundreds of volts.
[0026] The pump 400 further includes an anode 406 and a cathode 408
embedded in the substrate 402 adjacent to the slots 404 upstream
and downstream, respectively, to the slots 404. Electro-osmotic
pumping is driven in the narrow, deep slots 404. A cover 410, for
example constructed from glass, is bonded to the substrate 402. The
cover 410 may be anodically-bonded to the substrate 402.
[0027] The anode 406 and cathode 408 apply an external electric
field along the length of a capillary formed by the substrate 402
and cover 410 to generate electro-osmotic flow. The absence of
moving parts may enable relatively reliable operation.
[0028] New pump technology, such as electro-osmotic pumps, may
enable very compact form factors, thereby enabling many options for
electronic system design. Drip-less connections and valves may be
used to enable replacement of a defective pump while maintaining
cooling operation. Extra pumps may be added to a cooling system to
accommodate additional processors or higher power levels with new
generations of processors via higher liquid loop flow rates. For
example, a low-cost, single-processor liquid loop cooling solution
can be developed with a minimum number of pumps. The cooling
solution can accommodate higher heat loads or additional processors
through the addition of extra pumps. The basis loop can be shared
across multiple platforms with differing cooling requirements
according to the number of processors, ambient conditions, and the
like. For instance, a server specified for Network
Equipment/Building System (NEBS) compliance can attain system
cooling specifications by the addition of extra pumps while the
same system may use fewer pumps for typical corporate data center
usage.
[0029] Referring to FIG. 5, a schematic pictorial diagram
illustrates an embodiment of an electronic liquid cooling system
500 including a tubing 502 enclosing an interior bore or lumen
within which a cooling fluid can circulate, and a plurality of
pumps 504 having pluggable connections to the tubing 502
facilitating removal and addition of pumps 504 to the system 500.
The number of pumps 502 is at least one higher than a minimum to
meet system cooling specifications so that the pumps have a
suitable level of redundancy to enable reliable performance. The
electronic liquid cooling system 500 further includes a controller
506 capable of coupling to the plurality of pumps 504 and
controlling power levels of the individual pumps, enabling control
of fluid flow rate in the liquid cooling loop.
[0030] In some embodiments, the electronic liquid cooling system
500 can have paired connector banks 508 enabling replacement of the
pumps, for example using hot-pluggable access. The connector banks
508 include interior tubing in a selected configuration that
enables attached pumps 504 to be connected in various
configurations including parallel, serial, or a combination of
parallel and serial configurations.
[0031] In some systems 500, the number of pumps accommodated by the
paired connector banks 508 is sufficiently more than a minimum to
meet system cooling specifications so that less expensive and less
reliable pumps may be used with higher reliability. For example,
the amount of redundancy can be determined based on considerations
of reliability and cost of the pumps. A balance can be sought
between pump cost, mean time before failure in relation to cost,
and probability of failure of multiple pumps.
[0032] The connector banks 508 may also include one or more check
valves in selected locations, based on the particular pump
configuration, to prevent back-flow through any non-operating
pumps.
[0033] The controller 506 is capable of accessing information from
sensors determining various conditions such as the temperature of
electronics components cooled by the liquid loop, flow within the
tubing 502 at one or more locations, and condition of individual
pumps including pumping rate. The controller 506 can hold inactive
one or more redundant pumps that are non-operational or non-active
mode under normal conditions. The controller 506 can monitor
conditions and either predict or detect a failure condition, and
respond by activating the inactive redundant pump or pumps.
[0034] The controller 506 also operates to control pumping rate of
the individual pumps based on monitored values. In a particular
example, the controller 506 can detect the number of pumps 504
attached to the tubing 502 and the maximum heat load generated by
electronic devices and components 510 that are cooled by the
electronic liquid cooling system 500. The controller 506 uses the
information to determine and control power levels of the pumps.
[0035] In various embodiments, the electronic liquid cooling system
500 may also include cooling devices such as heat exchangers 512
and associated fans 514. A system 500 may include a storage
reservoir 516 that holds cooling fluid.
[0036] Referring to FIG. 6, a perspective pictorial diagram
illustrates an embodiment of an electronic system 600, for example
a computer server, including a chassis 602 including airflow inlet
and outlet vents 604, multiple components 606 including
heat-generating components mounted within the chassis 602, and an
electronic liquid cooling system 608. The electronic liquid cooling
system 608 includes a tubing 610 enclosing an interior bore or
lumen within which a cooling fluid can circulate. A plurality of
pumps 612 has pluggable connections to the tubing 610. The number
of pumps 612 is selected to be at least one higher than a minimum
to meet cooling specifications based on conditions imposed by the
heat-generating components 606. The electronic liquid cooling
system 608 also includes a controller 614 that can be connected to
the pumps 612. The controller 614 accesses various sensors to
determine thermal conditions internal to the electronic system 600
and controls power levels of individual pumps 612 based on the
thermal conditions to enable control of fluid flow rate in the
liquid cooling loop.
[0037] Reliability of the electronic system 600 is improved by the
addition of one or more redundant pumps 612. Additional pumps
eliminate a single point of failure and reduce potential system
reliability concerns. In an N+1 pump mode, pumps can operate at
lower power levels, reducing stresses on the system and improving
mean time to failure characteristics. Alternatively, in N pump
mode, redundant pumps may be deactivated until warranted by
conditions, for example a desire for additional pumping power.
Accordingly, N+1 pump mode supports higher power levels. N pump
mode supports lower power operation while improving
reliability.
[0038] The electronic liquid cooling system 608 may also include
one or more heat exchangers 616 coupled to the tubing 610. The
individual heat exchangers 616 include a tube segment enclosing a
segment interior lumen that passes the cooling fluid and extends
from a first end to a second end, a plurality of fins coupled to
the tube segment, and connectors coupled respectively to the first
and second ends to connect the heat exchanger 616 to the tubing
610.
[0039] The pumps 612 are coupled to the tubing 610 and capable of
pumping the cooling fluid through the tubing 610. The electronic
liquid cooling system 608 also includes the cooling fluid, in some
examples and ethylene glycol-based fluid although other suitable
fluids may otherwise be used. The cooling fluid is contained within
the tubing 610 and tube segments of the heat exchangers 616.
[0040] One or more fans 618 configured to drive air through the
heat exchangers 616 can be included in the electronic liquid
cooling system 608. In addition, one or more cold plates 620 may be
coupled to the tubing 610. The cold plates 620 are generally
attached to processors and other components 606, including
heat-generating or high-power components, to enable cooling of
localized heat sources.
[0041] The various heat exchangers 616 may have different shapes
and/or sizes in an arrangement that improves or optimizes volume
usage inside the chassis 602. Heat exchangers 616 may be added to
the liquid loop to exploit otherwise unused volume within the
electronics chassis 602, enabling usage of different sized fans 618
for heat exchangers 616 with different shapes.
[0042] Electronic system architectures such as server architectures
with a compact form factor may include the electronic liquid
cooling system 608 to accommodate increasing power and power
density levels of components including microprocessors and
associated electronics. The electronic liquid cooling system 608
uses the pumps 612 to drive the cooling fluid through high
pressure-drop channels of the cold plates 620 attached to
processors and other high-power components. The pumps 612 also
drive the cooling fluid along a potentially long and
narrow-diameter tube that completes the loop between the cold
plates 620, the heat exchangers 616, and the pumps 612. Forced-air
convection at the heat exchangers 616 removes heat from the
loop.
[0043] In a compact electronic system 600, for example a compact
server or computer system, cooling air is driven across the heat
exchanger 616 using tube-axial or blower fans 618 in close
proximity to the heat exchanger fins. Redundant fans 316 are
typically used for electronic systems 600.
[0044] The illustrative structures can be used to perform a
technique for cooling an electronic system 600 by configuring a
liquid loop cooling system 608 using multiple pumps 612. The number
of pumps 612 is selected to be at least one higher than a minimum
to meet cooling specifications based on thermal conditions within
the electronic system 600. The technique further includes
determining thermal conditions within the electronic system 600 and
controlling power levels of the individual pumps 612 based on the
thermal conditions.
[0045] In a particular mode of operation, the technique involves
maintaining one or more redundant pumps of the multiple pumps 612
as non-operational and predicting or detecting a failure condition.
In response to the failure condition, a redundant pump may be
placed into operation.
[0046] In other embodiments, the electronic liquid cooling system
608 can manage internal cooling by detecting the number of pumps
connected to the liquid loop cooling system 608 and detecting a
maximum heat load of the electronic system 600. Power levels of the
multiple pumps 612 can be controlled according to the detected
number of pumps and maximum heat load.
[0047] In particular embodiments, the electronic system 600 may be
a low-profile system, for example having a form factor of 1U or
less. Low-profile computer system installations present significant
thermal management difficulties. For example, Electronics Industry
Association (EIA) standard racks are commonly used to house
electronic equipment. In relatively large systems, for example 2U
or larger where "U" is the measuring unit for racks and
rack-mountable components with 1U=1.75" or 44.45 mm, most cooling
air enters through the front of the enclosure and exits through the
rear. For low-profile systems, the enclosure front is significantly
blocked by hard drives and media devices. The rear is blocked by
power supplies and input/output (I/O) connectors. To improve
cooling efficiency, 1U and 2U servers may incorporate the
illustrative electronic liquid cooling system 608 and incorporate
the multiple pumps 612 to ensure reliable pumping operation.
[0048] While the present disclosure describes various embodiments,
these embodiments are to be understood as illustrative and do not
limit the claim scope. Many variations, modifications, additions
and improvements of the described embodiments are possible. For
example, those having ordinary skill in the art will readily
implement the steps necessary to provide the structures and methods
disclosed herein, and will understand that the process parameters,
materials, and dimensions are given by way of example only. The
parameters, materials, and dimensions can be varied to achieve the
desired structure as well as modifications, which are within the
scope of the claims. Variations and modifications of the
embodiments disclosed herein may also be made while remaining
within the scope of the following claims. For example, although
particular geometries and configurations of multiple pumps are
shown, other arrangements are possible including additional groups
of series and/or parallel pump connection circuits. Also,
particular electronic system embodiments are illustrated, for
example a computer server. In other embodiments, the redundant pump
arrangements can be employed in other types of electronic systems
such as communication systems, storage systems, entertainment
systems, and the like.
* * * * *